Departing members of the House of Representatives awarded millions of dollars in extra pay to aides as they closed down their offices, according to lawmakers’ spending records.

The 96 lawmakers paid their employees $6.7 million, or 31%, more in the fourth quarter of 2010 than they did, on average, in the first three quarters of the year.

That’s about twice as much as the 16% increase awarded by lawmakers who returned to the 112th Congress, according to LegiStorm, an organization that tracks congressional salaries.

The disparity suggests retiring or defeated members used remaining funds in their official expenses budgets to boost salaries for staffers before they left Washington, cash that might otherwise have been returned to the U.S. Treasury.